A typical liquid crystal display (LCD) is capable of displaying a clear and sharp image through millions of pixels that make up the complete image. The liquid crystal display has thus been applied to various electronic equipment in which messages or pictures need to be displayed, such as mobile phones and notebook computers.
A liquid crystal display generally includes a plurality of pixel regions defined by a plurality of gate lines that are parallel to each other and a plurality of data lines that are parallel to each other and orthogonal to the gate lines. The liquid crystal display also includes a plurality of thin film transistors (TFTs), each of which is provided in the vicinity of a respective point of intersection of the gate lines and the data lines. Each pixel region includes a pixel electrode. The TFTs function as switching elements of the pixel electrodes. The gate lines are driven by a gate drive integrate circuit (IC). The data lines are driven by a data drive IC. The gate drive IC and the data drive IC are bonded on a printed circuit board (PCB) of the LCD. The gate drive IC and the data drive IC each connect with a respective flexible printed circuit board (FPC) via circuits on the PCB. The FPCs are separately bonded on the PCB. Mechanical and electrical connections between the gate and data drive ICs, the FPCs, and the PCB are achieved by anisotropic conductive films (ACFs).
Referring to FIG. 7, a typical LCD 1 includes a liquid crystal panel 10, a backlight module 20 adjacent the liquid crystal panel 10 for illuminating the liquid crystal panel 10, and a frame 30 accommodating the liquid crystal panel 10 and the backlight module 20. The frame 30 includes two separate pieces that are snap-fitted together to hold the liquid crystal panel 10 and the backlight module 20 therein.
Referring also to FIG. 8, the liquid crystal panel 10 includes a first substrate 11, a second substrate 12, and a liquid crystal layer 13 sandwiched between the first and second substrates 11, 12. Two adjacent edge portions of the first substrate 11 cooperatively define an L-shaped bonding region which is covered by an anisotropic conductive film (ACF) 15. The ACF 15 generally includes a polymer resin film having a plurality of conductive particles distributed therein. An isolation film is removably adhered on the polymer resin film. The isolation film is removed when the ACF 15 is ready to have electronic components attached thereon.
Referring also to FIG. 9, a plurality of drive ICs 14 of the LCD 1 are fixed and electrically connected to the first substrate 11 by the ACF 15. A process of bonding the drive ICs 14 on the ACF 15 generally includes the steps of: pressing the ACF 15 on the bonding region of the first substrate 11 in a low temperature environment; removing the isolation film of the ACF 15; disposing the drive ICs 14 on the ACF 15; and pressing the drive ICs 14 in a high temperature environment to fix and electrically connect the drive ICs 14 to the first substrate 11. The bonding region includes a plurality of connecting regions for supporting the drive ICs 14, and a plurality of spacing regions each defined between two adjacent connecting regions. The connecting regions include a plurality of connecting pins or bumps, which electrically connect with data lines and gate lines of the LCD 1.
The connecting pins or bumps of the gate lines and the data lines distributed in the connecting regions of the first substrate 11 result in the connecting regions being more elevated than the spacing regions. In the hot pressing process, a pressure produced by a pressing apparatus cannot be fully transmitted to the ACF 15 on the spacing regions, so that the bonding between the ACF 15 and the first substrate 11 in the spacing regions is relatively weak. Furthermore, when the isolation film of the ACF 15 is removed, portions of the ACF 15 on the spacing regions may be accidentally stripped off from the first substrate 11. This can also result in weakened bonding between the ACF 15 and the first substrate 11 in the connecting regions. Moreover, the ACF 15 in the spacing regions is not used or needed for connecting the drive ICs 14 to the first substrate 11. Because the ACF 15 is in general quite expensive, the cost of the LCD 1 is unduly high.
Therefore, a new electronic bonding structure that can overcome the above-described problems is desired. A liquid crystal panel having the electronic bonding structure is also desired.